1. Field of the Invention
The present invention is directed to circuitry and apparatus for detecting the presence of undesirable contaminants in fluids such as motor oil, transmission fluid, machine oil, diesel fuel, etc.
2. Description of the Prior Art
It is well known that contaminants in fluids will cause detectable changes in the dielectric constant of the fluid. These contaminants include, but are not limited to water, wear metals, sulfur, acids, anti freeze, and suspended hydrocarbons and other particulate matter.
Currently, expensive and time consuming chemical laboratory analyses are performed to determine the presence of these contaminants. U.S Pat. No. 301,401, Roof et al. discloses a dielectric constant detector employing a reference cell and a sample cell, each of which has plates therein which form capacitors. A fluid of known dielectric constant is placed in the reference cell while the fluid to be tested is passed through the sample cell. Using a pair of oscillators which apply energy to the cells, a signal indicative of the dielectric constant of the sample fluid is obtained.